If you are signed-in to the Amazon Chime iOS app using an Amazon account, you can delete you account from the Setting page. This is not applicable to Android, and does not apply to Enterprise accounts.
To do this:
1) Sign-in to the Amazon Chime iOS app with your Amazon account.
2) Go to Settings by clicking the gear icon in the upper left.
3) Scroll down and tap Delete account.
4) You will be redirect to a webpage to 'Close you Amazon account'. (This option is available via the iOS Amazon Chime app only, and does not apply to other methods of authentication e.g. Active Directory or Okta Enterprise accounts).
Important Note: Closing your Amazon account is permanent and applies to all Amazon products and services associated with the email address used.